This application claims the priority of German Application No. 199 01 083.8 filed Jan. 14, 1999, the subject matter which is incorporated by reference.
The invention relates to a method and a device for destroying drifting sea mines.
Drifting sea mines are moored mines that have been set adrift by the tearing or uncontrolled separation of their wire cable or chain from the anchor or mine base. Prerequisites for destroying these uncontrollably drifting sea mines include detecting and identifying them, and determining their position. This is effected, for example, with the use of sonar systems on specially-equipped ships, optronic viewing devices and visual observations. The drifting sea mines are destroyed through bombardment, by underwater drones or by the application of a destructive charge. A disadvantage of this type of destruction is the high cost of bombarding these sea mines, or the possibility that the mines will only be damaged, and not destroyed, meaning that dangerous ballast remains in the water. Moreover, the application of a destructive charge, for example by a diving apparatus, is both time-consuming and extremely dangerous.
U.S. Pat. No. 5,689,086 describes a cleanup system for cleaning up or clearing away simulated moored mines. A resilient latching shackle dropped from a ship is wound around a wire or a chain that connects the moored mines to an anchor or mine base. Two separate cables, to which the latching shackle is mounted, and two LFDs (Lateral Force Devices) are positioned around the moored mine, and prevent it from slipping out. Afterward, the moored mine is raised, with the anchor base, and taken on board. This system cannot be used to clear away drifting sea mines.
The use of underwater drones to clear away moored mines is described in an article entitled xe2x80x9cMinenbekxc3xa4mpfung [Combating Mines]xe2x80x9d from the periodical xe2x80x9cwt,xe2x80x9d No. 10/3/80, pp. 66 and 67. For locating the mine, a reference buoy is dropped into the water and the mine-searching sonar on the ship scans a strip approximately 350 m wide and 40 m in front of the device. After the mines have been located, or an underwater object resembling a mine, such as a land mine, has been located, an underwater drone to which, among other things, a camera is secured, is guided to the mine, and the camera is used to identify the mine. Guided solely by the sonar screen, the underwater drone subsequently places a charge, that will destroy the mine, next to the identified object. The underwater drone is then guided back to the ship and hauled onto the deck so the charge can be detonated. This underwater drone, however, can only be used to destroy sand-filled or grounded moored mines, not to clear away drifting sea mines.
Therefore, the need exists for a method and a device with which drifting sea mines can be successfully located and safely destroyed.
The above object is achieved according to a first aspect of the invention a method of destroying sea mines drifting in a body of water comprising the following steps of placing a buoyant body with a capture-and-destroy unit (11) into the water; using the buoyant body to bring the capture-and-destroy unit into the vicinity of the drifting sea mine; deploying a capture net having a beginning and an end from a capture unit of the capture-and-destroy unit to surround the drifting sea mine, with the capture net being oriented perpendicular to the sea mine; hauling the capture net into the capture unit by winding the end and the beginning of the net into the capture unit until the captured sea mine rests against a destroyer unit of the capture and destroy unit; and, automatically detonating a destructive charge of the destroyer unit to destroy the mine.
The above object is achieved according to a further aspect of the invention by a device for destroying drifting sea mines, comprising: a capture-and-destroy unit mounted to a buoyant body, with the capture and destroy unit including a capture unit and a destroyer unit, which are connected to the buoyant body, with the capture unit including a capture net which is deployed so that it surrounds a drifting sea mine; a buoyancy cord disposed at an upper edge of the capture net, and a plumb cord disposed at a lower edge of the capture net to orient the capture net perpendicular to the sea mine; the capture unit includes means, connected to the capture net, for drawing a beginning and an end of the capture net toward the capture unit until the sea mine rests directly against the destroyer unit; and a destructive charge integrated into the destroyer unit and connected to a detonation-and-safety device.
The concept underlying the invention is to employ a buoyant body having a coupled-on drive system to bring a capture-and-destroy device into the vicinity of the drifting sea mine and capture the mine; in the process, the sea mine is surrounded, and a capturing net, which is located in the capture device of the capture-and-destroy device, is deployed. A motorized device located in the capture device automatically draws the capture net tight until the captured sea mine lies directly against the destroyer device. Then, a destructive or effective charge is detonated. An advantage of this process is that the capture-and-destroy system autonomously reaches the mine position, or maintains the position after reaching it, and the destroyer unit is coupled directly for the reliable destruction of the mine. The destructive charge is positioned to penetrate directly into the effective portion of the drifting sea mine. With the use of a capture net having a width of about 1 m and a length of about 100 m, sea mines of widely-varying sizes can be capturedxe2x80x94in other words, the capture-and-destroy system operates independently of the shape and size of the sea mines, so small locating errors can be corrected, because the sea mine can be surrounded over a large area.
Additional features; and advantageous embodiments and modification are disclosed.
After the net has been deployed, the buoyant body provided with the drive unit can be de-coupled, and returns autonomously to the carrier ship for the purpose of re-use, which reduces costs.
In a simple embodiment, the capture-and-destroy system is manned without any threat to personal safety.
In a further embodiment, the capture-and-destroy system is embodied so as to operate completely autonomously. In this instance, the drive system includes drive motors, a navigation system with a navigation computer and a data-storage system. The navigation system comprises a GPS receiver (with antenna), a course-setting device and a course-measuring system. Prior to the start of the mission, mission data and position data relating to the sea mine are read into the data memory, for example through a manual programming device. It is also possible to correct the position data through radio or underwater-sound transmission. The use of a buoyant body permits control through visual contact, which effects an exact capture of the sea mine, which is also visible at the water surface. This can eliminate costly cameras.
The device of the invention is distinguished by a simple design and a high functioning reliability.
The invention is described below in detail by way of exemplary embodiments, in conjunction with the drawings.